soderstrom



2 Sheets-Sheet 1.

(No Model.)

A. SODERSTROM. TUBULAR DRILL.

Patented July 22, 1884.

llllll 1 7 ///A/////////////I///////l INVENTOR WITNESSES 2 q c ly ATTORNEY N. PETERS. Mmo-Um n hor. Wnhingtom D. c

,.2 Sheets-Sheet 2.

(NO Model.)

A. SUDERSTRUM.

TUBULAR DRILL.

No. 302,292. Patented July 22, 1884.

INVENTGR WITNESSES ATTORNEY N PETERS. Photo-Lilhognp llniTnn STATES PATENT @rrren.

ALBERT sonnns'rnoivr, OF STOGKHOLM, SWEDEN.

TUBULAR'DRILL.

SPECIFICATION forming part of Letters Patent No. 302,292, dated July 22, 1884.

(No model.)

To call whom it may concern:

Be it known that I, ALBERT SoDERsTRijM, a citizen of Sweden, anda resident of the city of Stockholm, in the Kingdom of Sweden, have invented a new and useful Improvement in Tubular Drills, of which the following is a specification.

The object of myinventionis to provide tubular drills of improved construction to beused for boring deep holes of medium or large caliber in metals, particularly in tough n1etals such as wrought-iron, soft steel, and copper, &c.which,in being worked,form long, continnous chips, niy improvement being designed to render unnecessary the withdrawal of the drill from the bore for removing the chips until the desired depth of bore has been reached.

My invention consists,'mainly, in the con struction of the cutting end and point of the drill and the manner of fastening it to atubular shank, and in the construction whereby the continuous chip is contracted in forming, so as not to clog the interior bore of the drill, and is continuously discharged through a side opening just below the head of the said drill, as will be hereinafter described and claimed.

In the accompanying two sheets of drawings,

1 Figure 1 represents a longitudinal central section of my improved tubular drill having flat cutting end. Fig. 2 is a longitudinal section of the same, taken through the line at m of Fig. 1. Fig. 3 is an end view of the cutting end of the same. Fig. 4 is an end view of the same provided with detachable bit or cutter. Fig. 5 is a detail section on about the line 1' y of Fig. 4. Fig. 6 is aside view (from the cuttingedge) of one of my tubular drills of the most preferred form, having conical cutting end.

i Fig. 7 is a side view of the same, seen in the direction of arrow 1 in Fig, 6. Fig. Sis an end view of Fig. 6.

The drill-shank A is tubular, provided with a conical head, a, having one or morefiattened surfaces, a, to prevent it from turning in the drill-chuck.

B is the bore or hollow portion of the tube A, and is curved at its outer end, and ending with an opening, I), in the side of the drillshank below the head a, as shown in Fig. 1. On the inside the end of the shank A is provided with flat threads 0, and is beveled at 0 upon its outer circumferential edge, as shown moreclearly in Fig. 5.

D is the cutting-head. This is threaded upon the outside for a certain distance at d, the thread corresponding with and fitting tightly into the aforesaid thread of the tube A, and at the end of the thread (1 the head D is provided with an inward bevel or groove, (2, which,- when the head 'D is screwed home into the tube, engages with and compresses toward the threads the beveled or conical surface of the tube A, thereby preventing any widening of the tube by extraordinary resistance to the drill, and consequent tendency to burst the lower end of said tube. should be made preferably of slightly larger diameter than the tube A, so as to make the latter work freely through the borethat is, without causing any friction against its sides. The bit E is either made in one piece with the head when of medium size, as in Figs. 1, 2, and 8, or it is made. in a separate piece inserted into the head, as in Figs. 4 and 5, the larger construction being always preferable for larger sizes, as it enables the same to be renewed and replaced with new ones (if broken) at slight expense. The cutting-edge e of the bitE projects a little below the opposite rounded edge, e, which guides the chip in about the same manner as the bit of a hand-plane, so that the size of the chip may be determined by the opening, in order that the drill may not be overstrained; and in the center of the bit and axis of the tube is a small hole, e around which the continuous spiral of the chip is cut and rises. From the boreB to the cuttingedge the cavity F in the cutting-headDis contracted in a conical, or preferably conoidal, shape, so that the chip, in rising through the said conoidal cavity into the tubular cavity -B,

. is contracted, as shown in Fig. 1, and thus its diameter is much less than that of the bore B, and consequently it cannot clog the latter; but as the drill descends the chip or borings will continuously issue through the side opening, Z), below the head a. Instead, however, of forcing the chip (after it has been cut) to bend into the conically spiral shape shown in Fig. 1 by the pressure of the inner wall of the cavity above the eutting-edge, (to which action the chip causes great resistance,) I have foundit to work better and take less power by curling the chipin cornucopia shape by the cuttingcdge itself, and I therefore prefer the conical cutting end shown in Sheet 2. The cone should be made tolerably acute and rounded off at the point, as indicated in dotted lines in Fig. 7. It will then work best,wear well, and when the cutting-edge shall have become dull may be ground down gradually until it assumes the obtuse shape shown in full lines without materially impairing its working capacity.

In order to provide for lubrication directly at the cutting end, I inclose in a groove upon the outer surface of the drill a fine oil tube or conduit running the entire length of the drill, from the extreme outer end of the head (tv to the cutting end, in a manner which I have described in a separate application for apatent.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. A metalboring drill consisting of the combination of the cutting-head I) with the tubular shank A, provided with the chuckhead a and side opening, I).

2. In combination with the tubular shank A, having side opening, Z), and head a, and with the cutting-head D, the oil-pipeG, placed in a groove continuous through the said shank and cutting-head and within the outer circumference of the drill and shank, substantially as and for the purpose hereinbefore set forth.

3. In a tubular drill, the combination of the shank A, provided with theinside rectangular threads, 0, and exterior end bevel, c, with the cutting-head D, having cxteriorly corresponding rectangular threads, 11, and a conical groove or bevel, d, engaging the said bevel c, as and for the purpose hereinbefore set forth.

4. In combination with the tubular shank A, the cutting-head D, provided with a conical or conoidal cavity, F, widening from the cutting-edge toward the bore 13, substantially as set forth.

5. In combination with the tubular shank A, the head D, having conical cutting end rounded at the point, and an internal cavity, F, widening from the cutting-edge toward the bore 13, substantially as specified.

6. In combination with the tubular drillshank A and with the cutting-head D, secured to the end of the said shank, the bit E, detachably secured to the said head D, substantially as and for the purpose set forth.

In testimony that I claim the foregoing as my invention I have signed my name, in presence of two witncsses,this 9th day of February,1883.

ALBERT sonnnsrnoiu.

\Vitnesses AUG. Yunnan, NERE A. ELFWING. 

